From 7fb0a5ee8889488f7568ffddffeb66ddeb50917e Mon Sep 17 00:00:00 2001 From: "Nikunj A. Dadhania" Date: Mon, 9 Apr 2012 13:52:23 +0530 Subject: perf kvm: Finding struct machine fails for PERF_RECORD_MMAP Running 'perf kvm --host --guest --guestmount /tmp/guestmount record -a -g -- sleep 2' Was resulting in a segfault. For event type PERF_RECORD_MMAP, event->ip.pid is being used in perf_session__find_machine_for_cpumode, which is not correct. The event->ip.pid field happens to be 0 in this case and results in returning a NULL machine object. Finally, access to self->pid in machine__mmap_name, results in a segfault later. For PERF_RECORD_MMAP type, pass event->mmap.pid. Signed-off-by: Nikunj A. Dadhania Reviewed-by: David Ahern Tested-by: David Ahern Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Nikunj A. Dadhania Link: http://lkml.kernel.org/r/20120409081835.10576.22018.stgit@abhimanyu.in.ibm.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/session.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 9412e3b05f6888..00923cda4d9c30 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -826,8 +826,16 @@ static struct machine * { const u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK; - if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL && perf_guest) - return perf_session__find_machine(session, event->ip.pid); + if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL && perf_guest) { + u32 pid; + + if (event->header.type == PERF_RECORD_MMAP) + pid = event->mmap.pid; + else + pid = event->ip.pid; + + return perf_session__find_machine(session, pid); + } return perf_session__find_host_machine(session); } -- cgit 1.2.3-korg